Gas-assisted scraping tool

Abstract

A gas-assisted scraping tool includes a housing having a blade support with a cavity that is connectable to a source of a pressurized gas; a blade attached to and extending forwardly of the blade support; and a diffuser attached to the blade support and spacing the blade from the cavity, the diffuser shaped to direct a stream of the pressurized gas from within the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas.

What is claimed is: 
     
       1. A gas-assisted scraping tool, comprising:
 a housing having a blade support, the blade support having a cavity that is connectable to a source of a pressurized gas; 
 a blade attached to and extending forwardly of the blade support; and 
 a diffuser attached to the blade support and spacing the blade from the blade support, the diffuser being flat and plate shaped and attached to the blade support to enclose and form a top wall of the cavity, and wherein the diffuser is shaped to direct a stream of the pressurized gas from within the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas. 
 
     
     
       2. The gas-assisted scraping tool of  claim 1 , wherein the blade support includes a rear wall, a pair of opposing side walls, a top wall, and a front lip, which together with either the diffuser or the blade define the cavity. 
     
     
       3. A gas-assisted scraping tool, comprising:
 a housing having a blade support, the blade support having a cavity that is connectable to a source of a pressurized gas; 
 a blade attached to and extending forwardly of the blade support, wherein the blade support includes a rear wall, a pair of opposing side walls, a top wall, and a front lip, which together with either the diffuser or the blade define the cavity; and 
 a diffuser attached to the blade support and spacing the blade from the cavity, the diffuser is flat and plate shaped, includes a plurality of spaced teeth extending across a forward edge thereof forming gaps therebetween, and is attached to the blade support to enclose and form a top wall of the cavity, and the plurality of spaced teeth are positioned between the scraping tool blade and the front lip such that the gaps, bounded by the scraping tool blade and the front lip, form a plurality of channels from the cavity spaced across the width of the scraping tool blade that direct the stream of the pressurized gas from the cavity lengthwise along the scraping tool blade; 
 wherein the diffuser is shaped to direct a stream of the pressurized gas from within the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas. 
 
     
     
       4. The gas-assisted scraping tool of  claim 3 , wherein the blade support includes a baffle that reduces air flow through the plurality of openings. 
     
     
       5. The gas-assisted scraping tool of  claim 4 , wherein the baffle includes a raised rib attached to and extending downwardly from the top wall into the cavity that forms a restriction with the diffuser to flow of pressurized gas from the cavity through the channels. 
     
     
       6. The gas-assisted scraping tool of  claim 5 , wherein the raised rib extends between the opposing side walls and is substantially parallel to the front lip. 
     
     
       7. The gas-assisted scraping tool of  claim 3 , wherein the rear wall, the opposing side walls, and the front lip each includes a mounting surface segment that engages the diffuser to close the cavity. 
     
     
       8. The gas-assisted scraping tool of  claim 7 , wherein the mounting surface segments combine to form a continuous, flat mounting surface that engages the flat, plate-shaped diffuser. 
     
     
       9. The gas-assisted scraping tool of  claim 8 , wherein the teeth are shaped to terminate rearwardly of a forward face of the front lip. 
     
     
       10. The gas-assisted scraping tool of  claim 1 , further comprising a retaining plate that releasably clamps the scraping tool blade against the diffuser, and the diffuser to the housing. 
     
     
       11. The gas-assisted scraping tool of  claim 2 , wherein the pair of opposing side walls diverge in a forward direction that substantially follows a portion of an outer profile of the scraping tool blade that overlies the blade support. 
     
     
       12. The gas-assisted scraping tool of  claim 10 , wherein the retaining plate is shaped to follow an outer profile of the blade support. 
     
     
       13. The gas-assisted scraping tool of  claim 1 , wherein the housing includes a handle. 
     
     
       14. The gas-assisted scraping tool of  claim 13 , wherein the handle is positioned rearwardly of the blade support and includes a fitting that connects to the source of pressurized gas. 
     
     
       15. The gas-assisted scraping tool of  claim 14 , wherein the handle includes a channel that connects the fitting to the cavity to convey compressed gas from the fitting to an opening in a rear wall of the cavity. 
     
     
       16. A gas-assisted scraping tool, comprising:
 a housing having a blade support, the blade support having a rear wall, a pair of opposing side walls, a top wall, and a front lip, all defining a portion of a cavity that is connectable to a source of a pressurized gas, and together forming a continuous, flat mounting surface; 
 a blade attached to and extending forwardly of the blade support; 
 a flat, plate-shaped diffuser abutting the continuous, flat mounting surface of the blade support, the diffuser spacing the blade from the blade support; and 
 wherein the diffuser is shaped to direct a stream of the pressurized gas outwardly from the cavity between the blade and the front lip in a lengthwise direction along an adjacent surface of the blade and distribute the compressed gas transversely across a width of the adjacent surface of the blade, whereby material loosened by the blade is blown away from an end of the blade by the compressed gas. 
 
     
     
       17. A method of making a gas-assisted scraping tool, the method comprising:
 forming a housing having a blade support, and forming a cavity in the blade support that is connectable to a source of a compressed gas such that the cavity can be filled with the compressed gas; 
 attaching a blade to the blade support such that the blade extends forwardly of the blade support; and 
 attaching a diffuser to the blade support such that the diffuser or the blade covers the cavity and spaces the blade from the blade support, wherein the diffuser is shaped to direct a stream of the pressurized gas from the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas. 
 
     
     
       18. The gas-assisted scraping tool of  claim 1 , wherein the diffuser includes a plurality of spaced teeth extending across a forward edge thereof forming gaps therebetween. 
     
     
       19. A gas-assisted scraping tool, comprising:
 a housing having a blade support; 
 a blade attached to and extending forwardly of the blade support; 
 a diffuser attached to the blade support and spacing the blade from the cavity, the diffuser shaped to direct a stream of the pressurized gas from within the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas; 
 the blade support having a rear wall, a pair of opposing side walls, a top wall, and a front lip that together with either the diffuser or the blade define a cavity that is connectable to a source of a pressurized gas; 
 a retaining plate that releasably clamps the scraping tool blade against the diffuser, and the diffuser to the housing, wherein the top wall of the blade support includes at least one boss extending into the cavity; and 
 at least one fastener that attaches to the at least one boss to clamp the scraping tool blade and the diffuser between the retaining plate and the blade support. 
 
     
     
       20. A gas-assisted scraping tool, comprising:
 a housing having a blade support, the blade support having a front lip and a cavity that is connectable to a source of a pressurized gas; 
 a blade attached to and extending forwardly of the blade support; and 
 a diffuser attached to the blade support and spacing the blade from the cavity, the diffuser including a plurality of spaced teeth extending across a forward edge thereof, forming gaps therebetween bounded by the blade and front lip to form a plurality of channels from the cavity to direct a stream of the pressurized gas from within the cavity lengthwise along the blade and distribute the pressurized gas transversely across a width of the blade, whereby material loosened by the blade is blown away from an end of the blade by the stream of the pressurized gas.